Summary: For biological products that are required to be sterile, testing mandated by the Code of Federal Regulations requires a 14 day incubation period, with observations based on visual examination of product-inoculated media, to conclude with reasonable confidence that the product is free from extraneous bacterial or fungal contamination. A group of newly emerging "rapid" methods suggests that such bacterial contamination can be detected in less than 14 days by other methods. The Microstar system, made by Millipore Corporation, utilizing bioluminescence to detect viable contaminating organisms, was selected for evaluation based on the laboratory's current use of existing Millipore Steritest equipment and supplies. Studies this year involved contamination introduced by injecting less than 10 CFU of selected organisms into various biological preparations. These "spiked samples" were subjected to traditional sterility testing and a hybrid sterility test where small quantities of the inoculated media was assayed daily using the MicroStar. The contamination was detected by Microstar 24-48 hours before turbidity was detected in the traditional sterility tests. The MicroStar system has shown the capacity for early detection of small quantities of environmental contaminants in conventional, adsorbed and cell based products. Prior incubation in USP and CFR specified sterility test media appears to enhance detection of multiple types of organisms; using the MicroStar filters, individual CFU's can be transfered and cultured for subsequent identification using selective media or enzyme based analysis.~~~~~